Brick-kiln and process of burning bricks.



W. H. PRANCNL BRICK KILN AND PROCESS OF BURNING BRICKS.

APPLICATION FILED JUNE 14, 1910.

Patented Oct. 11, 1910.

Aria 1 217252- m/flji a/zvov'a,

Zvirveaees THE NORRIS Pc'rsres co. \VASHINGTGII. o. c

WILLIAM H. FRANCIS,

OF CHERRYVALE, KANSAS.

BRICK-KILN AND PROCESS OF BURNING BRICKS.

Specification of Letters Patent.

Patented Oct. 11, 1910.

Application filed June 14, 1910. Serial No. 566,723.

1'0 all whom it may concern:

Be it known that I, WILLIAM H. FRANCIS, a citizen of the United States,residing at Gherryvale, in the county of Montgomery and State of Kansas,have invented an Improvement in Brick-Kilns and Processes of BurningBricks, of which the following description, in connection with theaccompanying drawings, is a specification, like letters on the drawingsrepresenting like parts.

My invention is a method of and apparatus for burning bricks (which termI use generically to include the application of heat in the manufactureof ceramic material for the production of what are sometimes calledbroadly, burnt clay products), and has for its primary objects theeconomy of fuel and more uniform heating and burning of the bricks,whereby not only is much fuel saved, but a considerable portion of theloss of bricks by uneven and improper burning is eliminated.

Explaining my invention more particularly in connection with an up-draftkiln, I provide openings in the form of ditches or valleys across thetop of the stack of green bricks between the latter and the usualsplatten or platted layer of bricks or other draftpreventing material,said openings being preferably directly above the fuel arches which arecommonly provided across the bottom of the kiln beneath the stackedgreen bricks. In connection with these stacks provided. with top ditchesor valleys and with the bottom arches, I provide connecting flues,either permanently in the kiln or removably mounted in connectiontherewith, whereby a more or less complete and continuous circulation ofair is provided through the separate portions of the burning bricks.Preferably also in connection with these flues I provide means forintroducing more or less steam and also promoting more or less forced.draft therein. In operation the circulation is not only maintained muchmore rapid and complete than in the ordinary manufacture of bricks, butthe volume is very largely increased and the localizing and distributionof the heat throughout all portions of the stack of burning bricks isrendered highly effective and is moreover subject to the accuratecontrol of the operator.

hIy invention will be more fully explained and the advantages thereofpointed out more at length in the course of the following descriptiontaken in connection with the accompanying drawings, in which I haveillustrated a preferred embodiment of the invention as applied toup-draft kilns.

In the drawings, Figure 1 is a transverse vertical sectional view of akiln embodying.

one form of my apparatus; Fig. 2 is a fragnentary View thereof in sideelevation looking toward Fig. 1 from the left; Fig. 3 is a fragmentaryview similar to Fig. 1 showing a modified construction, Fig. 4L is acentral longitudinal view of the kiln; and Fig. 5 is aview similar toFig. 2 showing a further adaptation of my invention.

Referring to the drawings, in which it will be understood that I havenot undertaken to go into all the well known constructional details ofbrick kilns but have confined the drawings to those features which arenecessary to an understanding of my invention and which constitute theapparatus portion of my invention, a stack 1 of green bricks is shown asin proper place between the usual side walls 2, 3, of 'a common form ofup-draft kiln. A splatten 4 is provided above the stack of bricks andbeneath the same or in the lower portion of the stack, usual fire arches5 are provided, communicating with openings 6 in the adjacent side wall2 through which I have herein shown the fire as delivered from oilburner nozzles 7 controlled by valves 8. I have shown this form of fuelsupply as convenient for purposes of description, but do not limit myinvention in any way thereto. In the upper portion of the stack andpreferablv at the very top thereof, I build or form openings, hereinshown as ditches or valleys 9, preferably extending transversely of thestack and preferably corresponding in number to the arches and locateddirectly above the same. As shown in Figs. 1 and 2, I provide in thewall 2 in alinement with these ditches or valleys transverse openings 10and at the outer end of these openings I connect pipes 11 whichterminate at their lower ends 12 in the openings 6 or arches 5.Preferably the fuel delivery nozzles or burners 7 pass into the lowerends 12 of the pipes and terminate within the same for the doublepurpose of creating draft and mixing more effectually with the currentof air passing through the pipes 11. Also preferably means is providedfor delivering a jet of steam into the pipe 11 at some point back fromits outlet, said means being herein shown as consisting of a nozzle 13regulated by a controlling valve 14, said nozzle being deflecteddownwardly into the pipe 11 just back of its lower end. Preferably asingle pipe 11 and the adjuncts just explained are provided to connecteach valley vertically with the fire arch or fuel supply openingimmediately below, as clearly shown in Fig. 2.

Instead of providing the independent pipes, corresponding flues 15 maybe built in the side wall 2, as shown in Fig. 3. My invention may bestill further amplified with corresponding advantages by providingremovable connections, preferably pipes, as shown at 16, 17 and 18 inFig. 5. Certain of the openings orvalleys may be covered by caps 19 andvarious lengths of pipes provided so as to connect different arches andvalleys diagonally or in such order as may be required throughout thekiln, this provision enabling the operator to direct special heat tospecial portions of the kiln and to smother or modify the heat at otherportions which possibly are being overheated. In other words, thisprovision makes it possible to regulate the heat to a nicety indifferent parts of the kiln while yet having the advantage of the freecirculation, great volume, etc., of my method as will now be explainedmore at length.

Having built up the bricks in the kiln in the manner above explained,the splatten is then put on the kiln over the whole top the same asusual. The ditches or valleys can be of any width or depth desired,according to the special exigencies of any particular plant, it beingremembered that it is not desirable to decrease the amount of the brickany more than possible and yet they should be of sufficientsize andnumber to promote the circulation and to localize the heat to thedesired extent. The pipes, when removable, are sealed tightly into thevalleys with mud, in the manner frequently employed by brick makers inother relations. As soon as the fires are lighted, the gas pressureflame exerts suflicientdriving impulse at the lower ends of the pipes tostart the circulation, thereby energizing the heat which would otherwisesimply circulate in well known manner through the stack of bricks up tothe splatten and more or less through the latter, so that instead ofhaving a sluggish circulation and simply wriggling out through thecrevices of the splatten, the heat now circulates back through the pipesor wall flues, Fig. 3) into the fire arches again, where it is mingledwith the new fire being delivered thereto from the oil burner nozzles 7and again driven forcibly through the stack of bricks. It is to be notedthat the waste heat or products of combustion delivered through thepipes 11 are used for circulation and preferably not at all for newflame. The oil or gas from the pipes 7 produces the flame andconstitutes the fuel supply, and the waste heat is returned to the kiln,not at a point prior to the flame (so as to mix with and therebyconstitute a part of the fuel, as in a usual mixing valve or Bunsenburner), but at a point where the flame has already taken place, but yetsufficiently near to the flame to get the influence of its rapidmovement and preferably to envelop or mingle directly with the newvolume of heat or flame being thus introduced. An amount of the productsof combustion or gases approximately equal to the amount of new fire orflame thus introduced, escapes through the splatten. Fresh air is usedexclusively for combustion (as is common and well-known with usual oilburners, typified at 7), and the gases from pipes 11 are used solely forvolume and circulation. They may be introduced wholly above the burner,as in Fig. 3, or around the burner, as in Figs. 1, 2 and 5. In the caseof coal fuel they would be introduced above the fire and not as a partof the draft supply.

In carrying out my method in its preferred and most complete manner, Ido not plat the splatten air tight at the start but leave it somewhatopen, preferably confining its open character to a strip longitudinallythrough the center, i. 6., transversely of the valleys 9. Also to stillfurther improve the fuel saving and heat distribution I introduce moreor less steam through the steam nozzles 13. The steam is not only hotand thereby contributes its heat to the flow of gases through the pipesor flues, but it has beneficial results in tempering the heat so thatbetter burning effects are produced. Also the steam jet cooperates withthe pressure of the natural gas or vaporized oil delivered through thefuel pipes to assist the circulation. The valleys tend to draw the heatand circulation toward them, thereby compelling the proper distributionof the latter from one end of the kiln to the other. The looseness ofthe splatten down the center tends to prevent the too rapid passage ofthe heat and the general arrangement produces a circulation whereby thewaste heat is returned again substantially to the same body of bricksthrough which it first circulated, by means of the combustion energy itscourse being subject however to slight variation within the discretionof the operator and according to the needs of the particular materialand special kiln in which my method is being employed.

While my invention is adapted to all kinds of fuel it is especiallyserviceable with gas burning, which requires particularly fullcirculation with large volume of air in addition to the relatively smallamount of mixed air and gas which directly supplies the flame.Accordingly I consider as among the principal advantages of my presentinparticular point, the burning of the bricks vention the fact that itsupplies this large volume of circulation without the necessity ofintroducing any cold air and without any tendency of pulling in cold airthroughout the splatten, all of said large circulation being suppliedthrough the waste heat.

It has been commonly considered neces sary, in burning ceramic material,to introduce a large amount of cold air to play on the material firsttouched by the fire, and to depend upon this cold air for supplying avolume of circulation, the aim having been thus to heat as little aspossible the material which is first reached by the fire, and to heat asmuch as possible the material which the fire touches later. I havediscovered that if only the volume is suflicient and possessessuflicient speed, very little or no cold air need be admitted to keepthe nearest ware from scorching, and that said volume may best beprovided by means of the waste heat (preferably from the same kiln)which, when moved along at said high speed and added to the new flame ornew heat (which is continuously supplied the same as before) gives notonly the protection required for the ware, but even burning, andsurprising efliciency and economy. The special means and manner ofdistributing and maintaining the vertical areas of heat circulation isof value irrespective of whether used in connection with this other mainfeature of my invention or not. I mention this in order that neither maybe considered as neces' sarily limited by the other (except in certainof the claims). I supply all of the fresh outside air to the burner thatis required for the gas or that the oil will take, and the combustion isimmediate and practically complete. In other words, I make no alterationin the fuel burner, supply, and combustion, which all remain exactly asbefore, but I feed the waste heat directly into the arch (not throughthe mixer of the oil burner, nor through the grate of the coal fire) sothat the volume and speed are secured through the medium of this hot airand thereby practically all the cold air is eliminated. By supplying theproducts of combustion for the volume of circulation, and by keepingthem at a relatively high speed of continuous circulation, I get rid ofall the use of cold air.

It will be understood furthermore that a large circulation is necessaryin burning bricks, because, for proper burning, a much greater heat isapplied to the bricks than they can absorb and if this heat stays in onelocality in the kiln as dead heat, it soon brings the bricks in thatlocality to a destructive temperature, whereas if this great heat isapplied to the bricks throughout the kiln as a hot blast only, or inother words is prevented from settling or stopping at any becomes moreuniform because of this distribution of the heat over the entire kilnand there are less rejects or improperly burned bricks. For thepreliminary water-smoking and in fact the initial burning of the stack,the splatten will ordinarily be first set loose together, to betightened as the volume of fire is increased, and preferably also sealedtight with mud (except preferably as stated through the center).

It will be understood that while I have herein set forth my mechanism inits pre ferred embodiment, many changes in form, arrangement andcombination of parts may be resorted to without departing from thespirit and scope of the invention in this particular, and the sameexplanation applies to a limited extent to the method, certain stepsthereof being capable of advantageous use without the others, all aswill be more apparent from the appended claims.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. The method, consisting of providing, in connection with a fuel flamefor burning bricks, a large circulation-volume of hot air at relativelyhigh speed, and delivering the latter under continuous forward movementadjacent and in the direction of the fuel flame but separate from andwholly distinct from the source of flame.

2. The method, consisting of providing, in connection with a fuel flamefor burning bricks, a separate large circulation-volume of hot air,delivering said hot air into the course of the flame to be therebyaccelerated in speed, and thence propelling said large volume of hot airand flame under continuous, rapid. movement to and through the bricks.

8. The method, consisting of providing, in connection with an alreadymixed fuel flame from an oil or gas burner for burning bricks, aseparate, large circulation-volume of hot air, and delivering said hotair at substantially continuous speed into the path of the flame fromsaid burner and subsequent to the ignition mixture.

4. The method, consisting of providing, in connection with a fuel flamefrom an oil or gas burner for burning bricks, a separate, largecirculation-volume of hot air, and delivering said hot air at relativelyhigh and continuous speed about the nozzle of said burner, whereby saidspeed is accelerated by the jet of flame from the burner.

5. The method, consisting of providing, in connection with a fuel flamefor burning bricks, a large circulation-volume of hot air at relativelyhigh speed, and delivering the latter adjacent the fuel flame butseparate from and wholly distinct from the source of flame, then passingthe hot air and products of combustion through the bricks and returningthe same as the supply of hotair for said circulation-volume.

G. The method, consisting of producing approximately vertical areas ofcontinuous heat circulation throughout a series of substantiallycontiguous portions of a stack of bricks being treated, and maintainingsaid circulation by returning to the primary source of heat a largevolume of heat from the previously delivered and otherwise waste heat.

7. The method, consisting of producing approximately vertical areas ofcontinuous heat circulation throughout a series of substantiallycontiguous portions of a stack of bricks being treated, maintaining saidcirculation by returning to the primary source of heat a large volume ofheat from the previously delivered and otherwise waste heat, andintroducing in the course of said circulation a restricted amount ofsteam.

8. The method, consisting of producing approximately vertical areas ofcontinuous heat circulation throughout a series of substantiallycontiguous portions of a stack of bricks being treated, maintaining saidcirculation by returning to the primary source of heat a large volume ofheat from the previously delivered and otherwise waste heat, andincreasing said circulation by steam jets delivered in the direction ofheat movement.

9. The method, consisting of supplying approximately vertical areas ofcontinuous heat circulation throughout a series of substantiallycontiguous portions of a stack of bricks being treated, maintaining saidcirculation by returning to the primary source of heat a large volume ofheat from the previously delivered and otherwise waste heat, andchecking said circulation appreciably along the top center of the stackof bricks.

10. The method, consisting of supplying approximately vertical areas ofcontinuous heat circulation throughout a series of substantiallycontiguous portions of a stack of bricks being treated, maintaining saidcirculation by returning to the primary source of heat a large volume ofheat from the previously delivered and otherwise waste heat, andshifting said areas as required to equalize or localize the heat forparticular localities in the kiln.

11. The method, consisting of supplying the main volume of gaseousmatter required for the heat distribution in a kiln by returning withforced draft the products of combustion from said kiln to the firedelivery point of the same kiln in front of the flame and subsequent tothe ignition mixture.

12. The method, consisting of supplying the main volume of gaseousmatter required for the heat distribution in a kiln by delivering alarge volume of the gaseous products of combustion to the primary source'of heat near the fire delivery point, and supplying fresh airexclusively for the purpose of fuel combustion.

13. In a brick-kiln, means to provide a fresh fuel flame for burningbricks, a source of hot air, means to deliver a large circulationvolumeof said hot air near the flame delivery point and separate from thecombustion, and means for propelling the fresh fuel flame and the saidseparate circulationvolume at high speed to and through the bricks.

14. In a brick-kiln, means to provide a fresh fuel flame for burningbricks, a source of hot air, means to deliver a large circulation-volumeof said hot air near the flame delivery point and separate from thecombustion, means for propelling the fresh fuel flame and the saidseparate circulation-volume at high speed to and through the bricks, andmeans for maintaining the circulation thereof through the stack ofbricks continuous.

15. In a brick-kiln, means to provide a fresh fuel flame for burningbricks, a source of hot air, means to deliver a large circulation-volumeof said hot air near the flame delivery point and separate from thecombustion, means for propelling the fresh fuel flame and the saidseparate circulation-vol ume at high speed to and through the bricks,and means for maintaining the circulation thereof through the stack ofbricks continuous, said last mentioned means including means to returnthe Waste gases to said delivery means to constitute the said circulation-volume.

16. In a brick-kiln, means to provide a fresh fuel flame for burningbricks, a source of hot air, means to deliver a large circulation-volumeof said hot air near the flame delivery point and separate from thecombustion, means for propelling the fresh fuel flame and the saidseparate circulation-volume at high speed to and through the bricks, andmeans for maintaining the circulation thereof through the stack ofbricks continuous, said last mentioned means including a plurality ofseparate passageways for the return of the Waste gases from the far sideof the kiln back to said delivering means.

17. In a brick kiln, means for producing a circulation of heat in aseries of approximately vertical areas throughout the stack of burningbricks, and means for returning from said individual areas portions ofthe heating medium and mingling the same in large volume withthe-primary source of heat, to be again delivered through the kiln.

18*. In a brick kiln, means for producing a circulation of heat in aseries of approximately vertical areas throughout the stack of burningbricks, means for returning from said individual areas portions of theheating medium and mingling the same in large volume with the primarysource of heat, to be again delivered through the kiln, and means forintroducing steam into the heating medium.

19. In a brick kiln, means for producing a circulation of heat in aseries of approximately vertical areas throughout the stack of burningbricks, means for returning from said individual areas portions of theheating medium and mingling the same in large volume with the primarysource of heat, to be again delivered through the kiln, andsteaminjecting means for accelerating the circulation.

20. In a brick kiln, means for producing a circulation of heat in aseries of approXimately vertical areas throughout the stack of burningbricks, and means for returning from said individual areas portions ofthe heating medium and mingling the same in large volume with theprimary source of heat, to be again delivered through the kiln,including means to vary the course or courses of the circulation todifferent portions of the bricks being burned.

21. A brick kiln, provided with a primary source of heat, and having aseries of passages between its top and bottom affording communicationfor the passage of waste heat from the burning bricks to said primarysource of heat, and steam jets opening into said passages in a directionto accelerate the flow of said waste heat and introduce steam thereto.

22. In a brick kiln, a series of passages for Waste heat from theburning bricks to the primary source of heat, and means for deliveringthe primary source of heat under pressure in an outward direction at theoutlet ends of said passages whereby the circulation is accelerated andthe waste heat is forcibly mixed with the fresh heat.

In testimony whereof, I have signed my name to this specification, inthe presence of two subscribing witnesses.

WILLIAM H. FRANCIS.

WVitnesses:

W. G. BUCKLES, H. A. Wim'sn.

